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- Herausgeber: John Wiley & Sons
- Kategorie: Wissenschaft und neue Technologien
- Serie: ISTE Invoiced
- Sprache: Englisch
The history of geosynthetics began over fifty years ago worldwide. It is still in the process of being written by engineers, researchers and enthusiasts, who see these products as a concrete response to the environmental challenges facing our society.
Geosynthetics from Yesterday to Today presents the basic concepts and notions required for the use, application, dimensioning and durability of these products, which have constantly improved over time to meet ever-changing technical and environmental challenges.
Based on experience acquired in France over several decades, this book establishes the soundness of these techniques and explains their concept and evolution. It is aimed at both beginners and experienced engineers, who are keen to learn more about this fascinating subject.
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Veröffentlichungsjahr: 2025
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Table of Contents
Cover
Table of Contents
Title Page
Copyright Page
Foreword
Acknowledgements
1 Geosynthetics: Function, Properties and Characterization
1.1. Definition
1.2. The various functions and applications of geosynthetics
1.3. Properties of geosynthetics and principal characterization tests
1.4. Developments and additions
1.5. References
2 Reinforcement
2.1. Introduction
2.2. Soil reinforcement mechanisms
2.3. Reinforcement geosynthetics and their characterization when used as reinforcement
2.4. Design and installation of geosynthetic reinforcements
2.5. References
3 Numerical Models Specific to Reinforcement
3.1. Introduction
3.2. Applying continuous modeling
3.3. Application of discrete modeling
3.4. References
4 Barrier and Drainage Functions: Non-hazardous Waste Landfills and Hydraulic Structures
4.1. Introduction
4.2. Geosynthetic barriers
4.3. Geosynthetic sealing systems
4.4. Drainage
4.5. Concept of equivalence
4.6. The impact of transfers within the barriers
4.7. Points to remember
4.8. References
5 Geosynthetic Filters: Uses, Feedback from Experience and Current Research
5.1. Introduction
5.2. General information on filtration using geosynthetics
5.3. Design methodology (compacted soils)
5.4. Geotextile filtration of a suspension or sludge
5.5. Feedback from experience from earthwork structures
5.6. Conclusion
5.7. References
6 Durability of Geosynthetics
6.1. Introduction
6.2. Main causes for the aging of geosynthetics
6.3. Impact of aging on the performance of geosynthetics
6.4. Conclusion
6.5. References
7 A Review of the Use and Behavior of Geosynthetics in France in the Past 50 Years
7.1. Relevance of a review of decades-old geosynthetic constructions
7.2. Older structures studied
7.3. Maraval (1976): dam with reinforced downstream wall
7.4. Prapoutel (1982): retaining structure in reinforced soil
7.5. Les Hospices de France (1987): retaining structure
7.6. Foix-Tarascon highway (1993): retaining structure
7.7. Lixing (1984): landslide stabilization using reinforced structures
7.8. Brides-les-Bains: reinforced segmental walls
7.9. Gif-sur-Yvette (1988): retaining structure
7.10. Frontenex (1992): cover for a spherical gas tank
7.11. Trois Lucs à la Valentine (1990): reinforcement over cavity
7.12. Roissard (1993): trench drain
7.13. Valcros
7.14. Ospedale (1979): upstream sealing on an earth dam
7.15. Aubrac (1986): upstream sealing of an earth dam
7.16. Jonage (1994): bank protection
7.17. Pont-de-Claix (1974): industrial reservoir
7.18. La Hague (1991–1997): cover lining for low-level activity nuclear waste disposal center
7.19. References
List of Authors
Index
End User License Agreement
List of Tables
Chapter 1
Table 1.1. Functions of geotextiles and geotextile-related products
Chapter 2
Table 2.1. Nominal characteristics associated with the reinforcement function ...
Table 2.2. Default values of the creep reduction factor (ΓCR*) (NF G38-064 (AF...
Table 2.3. Degree of severity of the installation conditions for a layer with ...
Table 2.5. Default values of the reduction coefficient (ΓCH*) as function of t...
Table 2.6. Standards validating the design and design elements of structures r...
Table 2.7. Geotechnical characteristics of the soil at the centre of the basin
Table 2.8. Reduction factors to be used for a polypropylene geosynthetic in th...
Table 2.9. Diagram of the undrained cohesions as a function of depth
Table 2.10. Geotechnical characteristics of the soft soil on which the Guiche ...
Table 2.11. Geotechnical characteristics of the soils and of the different soi...
Table 2.12. Development of the lining system–upstream soil interface and the f...
Table 2.13. Basic design hypotheses
Table 2.14. Results for short-term and long-term conditions and a cavity diame...
Table 2.15. Results of variations in the diameter in long-term and short-term ...
Table 2.16. The Foix-Tarascon highway – MS13: characteristics of the 21 m high...
Table 2.17. Comparison of the original design approach and the approach in acc...
Table 2.18. Comparison of factors applied to the geosynthetics in the original...
Table 2.19. Comparison of the ultimate tensile strengths when following the ap...
Chapter 4
Table 4.1. Hydraulic and dimensional characteristics and the flow across diffe...
Table 4.2. Types of geomembranes that can be prospected at the level of the sh...
Table 4.3. Statistics on the defects detected in covered geomembranes using ge...
Table 4.4. Empirical equations to predict the leakage rate in the case of circ...
Table 4.5. Empirical equations to predict the leakage rate in the case of long...
Chapter 6
Table 6.1. Residual mechanical strength of copoly(p-phenylene:3,4-diphenyl eth...
Table 6.2. Residual mechanical strength of poly(p-phenylene terephthalamide) f...
Chapter 7
Table 7.1. Older structures using geosynthetics presented in this chapter
Table 7.2. Prapoutel retaining structure with multilayer geotextile reinforcem...
Table 7.3. Changes in the geosynthetic characteristics sampled from the Prapou...
Table 7.4. Les Hospices de France: geometry and characteristics of the geosynt...
Table 7.5. Foix-Tarascon highway-MS13: geosynthetic-reinforced structure, 21 m...
Table 7.6. Original design conditions (1993).
Table 7.7. Geometric characteristics and characteristics of the geotextiles in...
Table 7.8. Trois Lucs à la Valentine: characteristics of the geometry and the ...
Table 7.9. Partial factors taken into consideration in the Eurocodes – Approac...
Table 7.10. Trois Lucs à la Valentine: comparison of the 1991 and 2017 design ...
Table 7.11. Roissard: characteristics of trench drains
Table 7.12. Roissard: evolution of flow over time for the different trenches a...
Table 7.13. Roissard: observations from trenches T2 to T5 in 2011, during the ...
Table 7.14. Results from the burst test on the bituminous geomembrane
Table 7.15. Evolution of the physical–chemical properties of oxidized bitumen...
Table 7.16. Aubrac dam: characteristics of the structure
Table 7.17. Jonage canal: characteristics of the geosynthetic-concrete mattres...
Table 7.18. Sites for the storage of radioactive waste based on its classifica...
Table 7.19. Maximum deformation of different types of geomembranes in a simple...
List of Illustrations
Chapter 1
Figure 1.1. Function – separating two layers of soil of different properties. ...
Figure 1.2. Filtration function – retention of fine particles.
Figure 1.3. Drainage function – collecting fluids.
Figure 1.4. Reinforcement through soil displacement.
Figure 1.5. Reinforcement geosynthetic: creating tension through a membrane ef...
Figure 1.6. Sealing geomembrane.
Figure 1.7. Protection of a geomembrane against puncture by angular granulates...
Figure 1.8. Erosion protection geosynthetic: protection against rain, wind, an...
Figure 1.9. Crack-inhibition geosynthetics for wearing courses.
Figure 1.10. Typical load-strain curve for a tensile test on a geotextile and ...
Figure 1.11. (a) Static puncture tests and (b) dynamic perforation test.
Figure 1.12. Permeability perpendicular to the plane without mechanical stress...
Figure 1.13. Determining in-plane flow capacity.
Figure 1.14. Determining the characteristic opening size.
Figure 1.15. Schematic depiction of the shear box test.
Figure 1.16. Schematic depiction of the inclined plane friction test.
Figure 1.17. Schematic depiction of the extraction box tensile grab test.
Chapter 2
Figure 2.1. Ziggurat constructed in Uruk.
Figure 2.2. Reinforcement and improvement of soils as per the standard NF P94-...
Figure 2.3. Example of single-layer geosynthetic reinforcement with uptake of ...
Figure 2.4. Illustration of the principle of reinforcing a soil with a multila...
Figure 2.5. Examples of the use of geosynthetic containers.
Figure 2.6. Different modes of deformation of the reinforcing elements used to...
Figure 2.7. Breaking down the properties of geosynthetics into functional char...
Figure 2.8. Typical development of a functional property as a function of the ...
Figure 2.9. Impact of installation and compaction on stiffness due to differen...
Figure 2.10. Impact of creep on tensile strength e (a) and on the deformation ...
Figure 2.11. Principle of the membrane effect
Figure 2.12. Demonstrating the membrane effect: (1) settlement d and (2) tensi...
Figure 2.13. Schematic diagram depicting displacements along the sheet over th...
Figure 2.14. Comparison of the anchoring forces mobilized in a centrifuge with...
Figure 2.15. Influence of the stiffness of the geosynthetics on the mobilizati...
Figure 2.16. Taking into account the shape of the geosynthetic, making use of ...
Figure 2.17. Geological profile of the project
Figure 2.18. Phases of the solution chosen
Figure 2.19. Schematic diagram of the path taken by the effective vertical str...
Figure 2.20. Aerial views of the structure in (a) 1986 and (b) 2019 (source: w...
Figure 2.21. View of the edge of the highway running north-west, that is, in t...
Figure 2.22. Test embankment in Bangkok (Long et al. 1997).
Figure 2.23. Development of the distribution of deformations of the geotextile...
Figure 2.24. Development of the vertical displacements under the embankment du...
Figure 2.25. Rotational failure of the embankment: (a) view of the step at the...
Figure 2.26. (a) Principle underlying the mechanism associated with the design...
Figure 2.27. Working principle of a thin layer on a slope (as per NF G38-067 (...
Figure 2.28. Forces at the level of the cover layer (as per NF G38-067 (AFNOR ...
Figure 2.29. Cross-section studied: the pore-pressures are governed by the hyd...
Figure 2.30. Diagram showing the effective normal stress (σ’ne) under the geom...
Figure 2.31. Sliding of the cover layer on its support t.
Figure 2.32. Schematic diagram depicting the forces at the soil–geomembrane in...
Figure 2.33. Schematic cross-section of the structure with notations. In accor...
Figure 2.34. Deformation of the geosynthetic above the cavity, and tensile for...
Figure 2.35. Typical cross-section of the MS13 structure on the A20 between Fo...
Chapter 3
Figure 3.1. Computation cycle in the DEM.
Figure 3.2. Microscopic parameters of a contact between two discrete, spherica...
Figure 3.3. Different kinds of behavior of a geosynthetic: (a) extension under...
Figure 3.4. Experimental setup: (a) dimensions; (b) photo; (c) position of the...
Figure 3.5. Comparison between the experimental tensile strength and shear str...
Figure 3.6. Comparison between the experimental deformation measurements and t...
Figure 3.7. Difference in the behaviors of a smooth geomembrane and a textured...
Figure 3.8. Modeling a geogrid using the discrete elements method: (a) triaxia...
Figure 3.9. Principle of the interaction between finite elements and discrete ...
Figure 3.10. Woven geosynthetic with two orthogonal reinforcement directions f...
Figure 3.11. Geosynthetic reinforcement characterized by three tensile strengt...
Figure 3.12. (a) Construction of a retaining wall made of geosynthetic tubes (...
Figure 3.13. Geometry of the discrete numerical model (Gorniak et al. 2013). ...
Figure 3.14. Comparison of the experimental and numerical loading curves (Gorn...
Figure 3.15. Distribution of tensile forces over the circumference of the geos...
Figure 3.16. Comparison of the numerical and analytical results (Gorniak et al...
Figure 3.17. Geometry of the numerical model (Huckert et al. 2014)
Figure 3.18. Comparison of the experimental and numerical results of surface s...
Figure 3.19. Comparison of the distributions of vertical stresses over the geo...
Figure 3.20. Evolution of the porosity of the fill as a function of the mode o...
Figure 3.21. Evolution of the distribution of principal stresses as a function...
Chapter 4
Figure 4.1. Example of a geosynthetic sealing system (from Comité français des...
Figure 4.2. Prescribed configuration for the passive and active barriers at th...
Figure 4.3. Example of an equivalent configuration of the passive barrier at t...
Figure 4.4. Types of defects detected using (a) the water jet method and (b) t...
Figure 4.5. Examples of circular defects and longitudinal defects and a concep...
Figure 4.6. Schematic diagram depicting the flow within a composite barrier in...
Figure 4.7. Image of flow areas under a geomembrane, caused by a defect with a...
Chapter 5
Figure 5.1. Pictogram of the filtration function as per the standard BS EN ISO...
Figure 5.2. Examples of geotextile filters: (a) needle-punched non-woven; (b) ...
Figure 5.3. Examples of the structure of woven geotextiles: (a) woven, made of...
Figure 5.4. Example of the structure of a non-woven geotextile with fibers ass...
Figure 5.5. Example of the structure of a knitted textile (source: INRAE)
Figure 5.6. Examples of drainage geocomposites composed by (a) and (b) a geote...
Figure 5.7. The mechanism for the self-filtration of soil, enabled by the geot...
Chapter 6
Figure 6.1. (a) Diagram of the microstructure of a semi-crystalline polymer; (...
Figure 6.2. Simplified depiction of the anisotropic shrinkage of materials and...
Figure 6.3. The efficiency of different types of antioxidants with temperature...
Figure 6.4. The three steps in chemical aging involved in the degradation of a...
Figure 6.5. Thermo-oxidation in the presence of excess oxygen (Bolland and Gee...
Figure 6.6. Simplified mechanism of the hydrolysis of polymeric chains
Figure 6.7. Tensile strain at break as a function of weight average molecular ...
Figure 6.8. Evaluation of the property retained of HDPE geomembranes up to 360...
Figure 6.9. Standard mechanism for PVC dechlorination
Figure 6.10. Mechanisms underlying the hydrolysis of PET
Figure 6.11. Evolution of the number average molecular weight over the aging t...
Figure 6.12. SEM images of PET-HT fibers: (a) not aged; (b) aged; (c) two year...
Figure 6.13. Evolution of the residual strength of PET fibers as a function of...
Figure 6.14. Chemical formula for (a) polyamide 6.6 and (b) polyamide 6
Figure 6.15. Chemical formula for (a) poly(p-phenylene terephthalamide) and (b...
Figure 6.16. Arrhenius diagram (in years) for the residual tensile strength to...
Chapter 7
Figure 7.1. Examples of the pioneering use of nonwoven textiles.
Figure 7.2. Cross-section of the Maraval dam with its reinforced downstream fa...
Figure 7.3. Woven PET used in the Maraval dam
Figure 7.4. Maraval dam.
Figure 7.5. Typical cross-section of the reinforced structure at Prapoutel as ...
Figure 7.6. Close-up of the geotextile used to reinforce the Prapoutel support...
Figure 7.7. Construction details of the reinforced structure at Prapoutel, bui...
Figure 7.8. View of the Prapoutel retaining structure at different times.
Figure 7.9. Reinforced embankment at Prapoutel in 2009.
Figure 7.10. Reinforced backfill at Prapoutel, with its UV protection, in 2013...
Figure 7.11. Principle of the EBAL-LCPC concept: the rigid reference that supp...
Figure 7.12. Phases in the construction of the structure on the “Hospices de F...
Figure 7.13. Hospices de France in 2016: (a) view of the geotextile facing beh...
Figure 7.14. Les Hospices de France: demonstration of the effectiveness of thi...
Figure 7.15. Foix-Tarascon highway-MS13: view of the construction of the third...
Figure 7.16. Foix-Tarascon highway-MS13: view of the third section of finalize...
Figure 7.17. Foix-Tarascon highway-MS13: (a) general view of the highway above...
Figure 7.18. Foix-Tarascon highway-MS13.
Figure 7.19. Foix-Tarascon highway-MS13: view of the placement of different in...
Figure 7.20. Foix-Tarascon highway-MS13: horizontal displacements during and i...
Figure 7.21. Evaluation of the forces generated by the sliding mass at the top...
Figure 7.22. Typical cross-section of the support solution for the Lixing land...
Figure 7.23. Photo of the structure supporting the Lixing landslide (1984).
Figure 7.24. Lixing (1984): deformation of the reinforced structure and extens...
Figure 7.25. View of the upstream block in 2016 (source: Photo V. Heili; Cerem...
Figure 7.26. Brides-les-Bains: (a) reinforced segmental wall; (b) aesthetic ap...
Figure 7.27. Brides-les-Bains: (a) cellular facing of a geotextile-reinforced ...
Figure 7.28. Highway A26–(Chalons-Troyes): (a) reinforced embankment with cell...
Figure 7.29. Highway A26: elevation and cross-section of the structure
Figure 7.30. A26: (a and b) Failure observed in 1991, shortly after constructi...
Figure 7.31. Brides-les-Bains (November 2017): (a) view of the whole structure...
Figure 7.32. (a) Plant for the on-site production of micro-reinforcement: the ...
Figure 7.33. Triaxial tests on the sand-fiber geocomposite: the shear strength...
Figure 7.34. View of a retaining wall built using micro-reinforced soil behind...
Figure 7.35. Gif-sur-Yvette in 1988: (a) view of the micro-reinforced structur...
Figure 7.36. Gif-sur-Yvette in 2016: (a) view of the micro-reinforced retainin...
Figure 7.37. Typical cross-section of a micro-reinforced covering layer on a s...
Figure 7.38. Micro-reinforced covering on the spherical gas tank: (a) covering...
Figure 7.39. View of the micro-reinforced sand covering during construction. ...
Figure 7.40. The Frontenex spherical tank in 2016: (a) micro-reinforced sand c...
Figure 7.41. Dismantling of the covering around the Frontenex tank in 2016: (a...
Figure 7.42. View of a localized collapse under the roadway at Trois Lucs à La...
Figure 7.43. Principle underlying geotextile reinforcement of a roadway over a...
Figure 7.44. Trois Lucs à la Valentine: (a) tensile behavior of the bimodular ...
Figure 7.45. Trois Lucs à la Valentine: view of the installation of the geotex...
Figure 7.46. Trois Lucs à la Valentine: (a) pavement that underwent localized ...
Figure 7.47. Trois Lucs à la Valentine: area repaired in 2016.
Figure 7.48. Different steps in verifying the ultimate limit state correspondi...
Figure 7.49. The different steps in the verification of the serviceability lim...
Figure 7.50. Difference in the 1991 and 2017 design approaches.
Figure 7.51. Typical cross-section of one of the trench drains.
Figure 7.52. Roissard (1993): view of a trench drain during construction, with...
Figure 7.53. Roissard: typical cross-sections of different trenches (geosynthe...
Figure 7.54. Roissard: observations from 2011 for T2, without any geotextile.
Figure 7.55. Roissard: observations from 2011 for trench T3, with the nonwoven...
Figure 7.56. Cross-section of the Valcros dam showing the location of the upst...
Figure 7.57. Soil granulometry of the homogeneous earthen dam in Valcros
Figure 7.58. (a) Construction of the upstream face; (b) construction of the to...
Figure 7.59. (a) Downstream face; (b) upstream face (2014).
Figure 7.60. (a) Erosion in 1972 of the unconfined geotextile face; (b) erosio...
Figure 7.61. (a) Samples taken in 1992 from the upstream face; (b) view throug...
Figure 7.62. Excavation from 1992 and sampling from the foot of the dam at the...
Figure 7.63. Linearized granulometry curves for the initial soil found at Valc...
Figure 7.64. Typical external upstream sealing system: (a) exposed geomembrane...
Figure 7.65. General view of the Ospedale dam in 2016.
Figure 7.66. Cross-section of the Ospedale dam.
Figure 7.67. Details of the upstream geomembrane sealing (GBR-B bituminous geo...
Figure 7.68. Ospedale dam: installation of the sealing layer.
Figure 7.69. Ospedale dam: (a) connecting the sealing system at the foot; (b) ...
Figure 7.70. Ospedale dam: leakage rate over time
Figure 7.71. Ospedale dam: self-locking protective blocks during the draining ...
Figure 7.72. Ospedale dam: sampling campaign: (a) location of the samples; (b)...
Figure 7.73. Hydraulic conductivity test on the geomembrane
Figure 7.74. Aubrac dam: (a) upstream view (2016); (b) installation of the pro...
Figure 7.75. Aubrac dam: cross-section of the upstream sealing at the toe of t...
Figure 7.76. Aubrac dam: connection between the PVC geomembrane and the vertic...
Figure 7.77. Aubrac dam: exposed geomembrane during construction (1986).
Figure 7.78. Aubrac dam: (a) sampling campaign; (b) burst testing; (c) evoluti...
Figure 7.79. Aubrac dam: view of the sliding of the geomembrane and the protec...
Figure 7.80. Aubrac dam: detailed view of the sliding at the interface between...
Figure 7.81. (a) The IRSTEA inclined place simulating the multilayer interface...
Figure 7.82. Jonage: typical cross-section of the bank protection using a geos...
Figure 7.83. Jonage: (a) installation of the geosynthetic mattress in 1994; (b...
Figure 7.84. Jonage canal: (a) view of the sealing mattress at the end of the ...
Figure 7.85. Location of the reservoir of the Perstorp chemical factory in Pon...
Figure 7.86. Double liner used in the Pont-de-Claix reservoir.
Figure 7.87. (a) Pulverization of the bitumen for the secondary liner; (b) sec...
Figure 7.88. Drainage layer on the secondary liner.
Figure 7.89. (a) Cracks in the stabilized-gravel drainage layer; (b) bridging ...
Figure 7.90. (a) Installation of the primary butyl liner; (b) anchoring of the...
Figure 7.91. Locating the leak in 2004 at the level of the water intake (photo...
Figure 7.92. View of the reservoir in 2011.
Figure 7.93. Appearance of the butyl geomembrane at the anchoring level in 201...
Figure 7.94. CSM at La Hague: general view of the site with vegetated cover-li...
Figure 7.95. CSM at La Hague: typical cross-section of the cover liner and pho...
Figure 7.96. CSM at La Hague (1991): (a) construction and storage phase; (b) i...
Figure 7.97. CSM at La Hague: hydraulic balance between 1999 and 2009
Figure 7.98. CSM at La Hague, vertical settlement between the end of construct...
Figure 7.99. CSM at La Hague: (a) slow sliding over the slope, 20 years after ...
Figure 7.100. CSM at La Hague (2010–2011): (a) site visit close to the zone of...
Figure 7.101. CSM at La Hague: burst testing on the bituminous geomembrane sam...
Figure 7.102. CSM at La Hague: diffusion tests on the bituminous GBR samples c...
Figure 7.103. CSM at La Hague: tomography on virgin samples under tensile stre...
Guide
Cover Page
Table of Contents
Title Page
Copyright Page
Foreword
Acknowledgements
Begin Reading
List of Authors
Index
Wiley End User License Agreement
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SCIENCES
Mechanics, Field Director – Gilles Pijaudier-Cabot
Geomechanics, Subject Head – Gioacchino Viggiani
Geosynthetics from Yesterday to Today
55 Years of French Experience
Coordinated by
Pascal Villard
First published 2025 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.
Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:
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© ISTE Ltd 2025The rights of Pascal Villard to be identified as the author of this work have been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s), contributor(s) or editor(s) and do not necessarily reflect the views of ISTE Group.
Library of Congress Control Number: 2024952939
British Library Cataloguing-in-Publication DataA CIP record for this book is available from the British LibraryISBN 978-1-78945-175-7
ERC code:PE1 Mathematics PE1_7 TopologyPE10 Earth System Science PE10_5 Geology, tectonics, volcanology
Foreword
J.P. GIROUD
Consulting Engineer and Expert, Paris, France
It gives great satisfaction to be associated with a knowledge-sharing project. The satisfaction is even greater when the project is the product of a collective endeavor. The satisfaction becomes immense when the project is the result of decades of innovation carried out within a dynamic community. And when the project is carried out within a discipline as essential as that of geosynthetics, then the sense of satisfaction doubles at the thought of the public good it serves.
This collective work has produced a book that blends theoretical and practical approaches. This book does not claim to be exhaustive but nonetheless offers a rich and amply illustrated database relevant to the activities of all types of readers. Thus, manufacturers, designers, constructors, and inspectors will find practical and well-laid out information, while teachers and students in engineering courses will find supporting material for their classes, and researchers will find inspiration for future endeavors.
This book comes at a time when geosynthetics are required to play an essential role in a century where it has become so important to protect our environment: conservation and equitable distribution of water, prevention of pollution, protection of coastlines, prevention of soil erosion, reinforcement and drainage of slopes to prevent landslides, reduction of construction material transport by promoting the use of local resources, optimal use of all kinds of materials (especially recycled products) in civil engineering projects, improvement and construction of roads, railways and waterways, and many other challenges.
This book also offers a historical perspective, as it bears witness to the extraordinary growth of geosynthetics in France for over fifty years now, in tandem with the growth of the remarkable French Committee on Geosynthetics (CFG). Indeed, this book is born out of the work of passionate engineers and innovators, some of whom contributed to the earliest rise of geosynthetics, in particular by participating in the development of these products, the refinement of techniques, the development of design methods and norms, the dissemination of knowledge, and the democratization of the various applications of geosynthetics. This long history allowed the authors to step back and take the long view. Thus, the information provided in this book is based on considerable experience. In fact, the last chapter is dedicated to experience drawn from the observation of the behavior of older structures incorporating geosynthetics constructed in France.
It is important to note that the authors of the different chapters in this book have engaged in diverse professional fields. At various points in their career they have been involved in all the activities that make up the geosynthetics discipline, namely: manufacturing geosynthetics, developing new geosynthetics, carrying out tests on geosynthetics and analyzing their results, conducting research on geosynthetics and their applications, perfecting and publishing design methods for applications of geosynthetics, integrating geosynthetics into the civil engineering syllabus, developing norms and quality-control methods related to geosynthetics, promoting the certification of geosynthetics, designing projects involving geosynthetics, installing and inspecting geosynthetics in the field, monitoring the behavior of projects that incorporate geosynthetics, evaluating the performance of geosynthetics in different kinds of projects, etc. The range of authors in this book illustrates a core feature of the discipline of geosynthetics: the intense cooperation between professionals with different training and competencies.
The authors of this book participate actively in international conferences on geosynthetics and are well aware of the treasures available in the international literature on geosynthetics. However, they found ample material in French publications to serve as sources of technical information and data for the preparation of this book initially published in French. As it provides an opportunity to a wide spectrum of readers to access the wealth of experience accumulated in France over decades of uses of geosynthetics, this English version of the book is an important contribution to the international literature on geosynthetics. This English version opens up the realm of French experience to the international community of geosynthetics. This Foreword cannot ignore this essential characteristic of the book and, naturally, mentions the French experience from the innovations of the era of pioneers to the modern achievements.
This book gives the reader a chance to review the essential role that France has played in developing the discipline of geosynthetics. The first impetus came from the industrial production in France, from 1967 onwards, of nonwoven fabrics, which would be known as ‘geotextiles’ ten years later. Thanks to their many applications, these materials quickly became indispensable in civil engineering projects. The role played by the manufacturers is essential: let us not forget that the geosynthetics discipline would not exist without geosynthetics and, therefore, without the manufacturers. French manufacturers must be credited, in particular, for the in-factory production of bituminous geomembranes from the 1970s onwards, which is unique on a global level, and for the development of innovative geosynthetics such as multilayer geotextile filters, drainage geocomposites, and geosynthetics equipped with sensors.
As a result of the initial impetus from the manufacturers, French engineers pioneered the design and implementation of a number of geosynthetic applications: unpaved roads stabilized using geotextiles (as soon as 1968), the first embankment on compressible soil reinforced by geotextile (1969), the first use of nonwoven geotextiles as in-soil filters (1970), the first use of a geotextile as a filter within a dam (1970), the first vertical wall reinforced with geotextiles (1971), the first use of a geotextile to protect a geomembrane (1971), the first use of a geomembrane in a double liner system (1971), the first double liner system using two geomembranes (1974), the first entirely geosynthetic double liner system using two geomembranes separated by a drainage geocomposite (1981), and the first use of a drainage geocomposite in a dam (1985). These French innovations inspired designers and builders around the world and contributed to geosynthetics revolutionizing civil engineering.
The success of the first applications of geosynthetics and the success of subsequent applications were only possible because of the quality of the geosynthetics used. This is again an area where France played an important role, being the arena where several novel laboratory tests were developed. For instance: shear tests using specially constructed shear boxes for testing interfaces containing geosynthetics; tests to measure the watertightness of geomembranes; tensile tests on wide specimens of geotextiles; and tests to assess the puncture resistance of geomembranes in contact with soil samples representative of the field conditions. Another example is the development in France of the certification processes for geosynthetics (to ensure their reliability), which are now an example for the international community. Several French experts have played, and continue to play, an important role in the development of European and international norms and testing standards governing the quality of geosynthetics.
The French have provided an intellectual impetus to the discipline of geosynthetics. Thus, French authors (both researchers and engineers) were pioneers in the development of design concepts and methods relating to several geosynthetic applications. These are, notably: stabilization of unpaved roads using geosynthetics, stability and anchorage of geosynthetics on slopes, criteria for geotextile filters, quantification of the resistance and deformation of geosynthetics that support loads over cavities and depressions, evaluation of leakage through geomembrane liners, and sizing of drainage layers associated with geomembrane liners. As early as in the 1970s, French engineers identified and defined the basic functions of geotextiles and formulated the concept of double liner systems using geomembranes, which are essential in protecting the environment. Similarly, the terminology of the geosynthetics discipline owes its character to France: the terms géotextile and géomembrane, first written in French and then adopted around the world, led naturally to the term “geosynthetics” as well as other “geo-” terms, and probably even inspired a certain “geomania” among other disciplines and other languages!
We would also be remiss in not highlighting that France had a considerable influence on the recognition of the discipline of geosynthetics and on organizing activities within this discipline. There is no dearth of examples: the first International Conference on Geotextiles (Paris, 1977), subsequently recognized as the first International Conference on Geosynthetics; the initiation of the first national committee dedicated to geotextiles (1978), the CFG, which was later expanded to include all geosynthetics; the French initiative (1982) of the creation of the International Geotextiles Society (IGS), which was officially founded in Paris (1983) and which then became the International Geosynthetics Society. At the time of writing, France is the only country, apart from the United States, to have organized two International Conferences on Geosynthetics (Paris 1977, Nice 2002).
It is clear that this book is a direct continuation of the saga of geosynthetics in France and is a testament to the vitality of the French geosynthetics community. The English version of this book is a bridge between the French experience and the international community of geosynthetics. Going beyond the immediate applications of this book, the spirit of cooperation that led to the book being created must propel future generations to continue sharing knowledge, following in the footsteps of the pioneers of the geosynthetics discipline. This will be the lasting significance of this book.
Acknowledgements
The authors would like to thank all of those who helped them with the proofreading of the English version of this book, in particular Mr Howard Murray for his expert proofreading of several chapters and Professor Marina Pantazidou for proofreading the preface.
1Geosynthetics: Function, Properties and Characterization
Pascal VILLARD
Laboratoire 3SR, Université Grenoble Alpes, France
1.1. Definition
According to the EN ISO 10318-1 (BSI 2015a) standard, a geosynthetic (GSY) is a product, at least one of whose components is made from a synthetic or natural polymer, in the form of a sheet, a strip or a three-dimensional structure used in contact with soil and/or other materials in geotechnical and civil engineering applications.
This definition covers a very wide group of products of different appearance, whose principal functions include drainage, filtration, separation, reinforcement, protection, surface erosion-control, sealing, stabilization and crack inhibition or stress relaxation.
Sometimes used in combination with one another, these products cover a wide range of applications, considering the technical and economic advantages they afford when compared to traditional construction solutions. They are products where at least one of the components is a geosynthetic product are called “geocomposites”.
The majority of geosynthetics are products manufactured from petrochemical polymers. More recently, research has been carried out around the world to respond to environmental challenges and to develop the use of recycled or even natural polymers.
Geosynthetics are divided into three categories depending on their type or their field of application:
geotextiles (GTX) and geotextile-related products (GTP);
geomembranes (GBR);
geosynthetic clay barriers (GBR-C).
1.1.1. Geotextiles and geotextile-related products
GTX and GTP are mainly used to separate two layers of soils with different mechanical and hydraulic characteristics, filtration and drainage, reinforcement, controlling surface erosion, stabilizing and crack inhibition or stress relaxation and protecting GBR. Conventionally, GTX are permeable polymer textile products (natural or synthetic polymers: polypropylene, polyethylene, polyamide, and polyester), which can be nonwoven (GTX-NW), knitted (GTX-K) or woven (GTX-W). Woven products are made from monofilaments, multifilament yarns or tapes. Nonwoven GTX may be needle-punched or heat-bonded. Knitted GTX make it possible to join together several elements, one or more threads, filaments or other components, or even a geotextile, by interweaving them using one or more yarns. GTP are products made up of material that is planar, permeable and with a polymer base (synthetic or natural), which are used in contact with soil or other material in the field of geotechnics and civil engineering, and which do not match the definition of a geotextile. This family includes geogrids (GGR), geonets (GNT), geocells (GCE), geomats (GMA) and geospacers (GSP).
It can be seen that GTX and GTP can be made from natural materials (made up of natural fibers: jute, linen, hemp, coir, cotton, straw, etc.). They are chiefly used for separation, filtration, drainage, slope protection and erosion control or as reinforcement in temporary structures, given that they are biodegradable.
1.1.2. Geomembranes
Geosynthetics that offer a barrier to prevent or limit the migration of fluids (GBR, commonly called geomembranes in France) take the form of flexible sheets that are thin and impermeable, offering sealing against liquids and gases. The EN ISO 10318-1 (BSI 2015a) standard defines terms related to geosynthetic sealing systems (DEG) as well as the structure, manufacture and assembly of GBR.
It defines:
polymeric geosynthetic barriers (GBR-P);
bituminous geosynthetic barriers (GBR-B);
clay geosynthetic barriers (GBR-C) also geosynthetic clay liner (GCL).
GBR-P are made up of different polymers (high-density polyethylene (HDPE), flexible polypropylene (PPF), plasticized polyvinyl chloride (PVC-P) and ethylene propylene diene terpolymer (EPDM) and are produced by extrusion, calendering or impregnation.
GBR-B are made from a structure that is assembled in a factory. This structure is made up of geosynthetics and has the form of a sheet. The bitumen chiefly provides the sealing or barrier function.
1.1.3. Geosynthetic clay barriers
GBR-C, EN ISO 10318-1 (BSI 2015a), are made from a factory-assembled structure consisting of geosynthetics and in the form of a sheet in which the barrier function is essentially fulfilled by clay. It is important to note that bentonite geosynthetics only realize their sealing function after being wetted in place after they are laid, and this must be done under a confining soil layer.
1.1.4. Standard practices
In France, the implementation of geosynthetic solutions is supported by standard practices that guide project managers and contractors in the safe planning, designing and implementation of these different products. Geosynthetic products and their applications are governed by a quality certification that is based on standardized tests developed in partnership with the profession. The Comité Français des Géosynthétiques (French Geosynthetics Committee), which brings together producers, research bodies, project managers, contractors, consulting engineers, public works companies, and building contractors, is the main actor in France. This body compiles knowledge in the field, disseminates information to users, promotes the use and development of geosynthetics and new techniques, and, finally, supports standardization in France, Europe and around the world.
1.2. The various functions and applications of geosynthetics
The main functions performed by geosynthetics are as follows: separation, protection, filtration, drainage, reinforcement, sealing, erosion protection and stress relief (crack inhibition). Generally speaking, each geosynthetic performs a specific function. However, certain geosynthetics may carry out several functions simultaneously. The harmonized European standards have listed and associated the various functions of geosynthetics with the many geotechnical applications for which they are used (Table 1.1).
Table 1.1.Functions of geotextiles and geotextile-related products
Function
Separation
Protection
Filtration
Drainage
Reinforcement
Sealing
Anti-erosion
Anti-fissuring
Application
Laying roads and railway lines
X
X
(1)
X
Drainage work
X
X
X
Riverbanks and coastlines
X
X
(1)
X
X
Canals
X
X
X
(1)
X
X
X
Dams and reservoirs
X
X
X
(1)
X
X
X
Supports and foundations
X
X
(1)
X
Tunnels
X
(1)
(1)
X
Landfill (solid waste)
X
X
X
(1)
X
X
X
Landfill (liquid waste)
X
X
X
(1)
X
Pavements
X
X
X
(1) For drainage systems, refer to the application “Drainage Works”.
COMMENT ON TABLE 1.1.− Functions associated with the geotechnology applications in which they may be used as per the harmonized European standards: EN 13249 (BSI 2016a), EN 13250 (BSI 2016b), EN 13251 (BSI 2016c), EN 13252 (BSI 2016d), EN 13253 (BSI 2016e), EN 13254 (BSI 2016f), EN 13255 (BSI 2016g), EN 13256 (BSI 2016h), EN 13257 (BSI 2016i), EN 13265 (BSI 2016j), EN 13361 (BSI 2018a), EN 13362 (BSI 2018b), EN 13491 (BSI 2018c), EN 13492 (BSI 2018d), EN 13493 (BSI 2018e), EN 15381 (BSI 2018f) and EN 15382 (BSI 2018g).
1.2.1. Separation
GTX were initially developed to separate two soil layers with different characteristics: a subgrade from a sub-base layer or several sub-base layers with different gradings.
They allow the different layers to retain their respective properties while preventing migration or the contamination of one layer by another. Their function was therefore to prevent the mixing of adjacent layers without obstructing the movement of fluids (Figure 1.1).
Figure 1.1.Function – separating two layers of soil of different properties.
These products are not subjected to significant tensile stress, but they must be capable of resisting local puncturing forces. They are designed considering their resistance to tensile stress and to puncturing, their extension under maximum load and their opening size (the dimension of the largest particle that can pass through the product).
This function is used for roadways like temporary roads or roads with low traffic values in order to minimize the formation of ruts (access roads to a work-site or forest roads), or to ensure the longevity and durability of transport infrastructure such as the base layers of roads, freeways and railways lines. They are also used in geotechnical projects when materials with very different properties have to be used together, for example, in the construction of landfills on compressible soils.
1.2.2. Filtration
Filtration is the geosynthetic’s ability to retain soil particles whose diameter is larger than a given nominal value while allowing the passage of fluids in a direction perpendicular to its plane (Figure 1.2). This function is typically required in drainage systems, where the geosynthetic must allow water from the zone being drained to pass through and flow toward the drain, while at the same time preventing the clogging of the drain by fine particles, and preventing the progressive erosion of soil upstream of the drain.
Geotextile filters can be used in many projects, for instance, hydraulic structures (dams, basins, canals, dikes, etc.), earthwork projects, embankments on compressible soils, roadways, engineering structures, foundations and waste-storage facilities.
Figure 1.2.Filtration function – retention of fine particles.
The challenge in designing geosynthetic filters is to optimize their filtration opening sizes (in mm), which governs their ability to obstruct or allow the passage of fine particles of a given size. This will allow the passage of fluids while ensuring a specified flow rate and also preventing the migration of fine elements from one medium to another (internal erosion of the soil). It must also prevent the clogging of the product, which could in the long term make it ineffective and could compromise the durability of the structure (interstitial excess pressures could damage its stability).
1.2.3. Drainage
Drainage is the function of collecting fluids and transporting them toward an outlet (Figure 1.3). The transport is parallel to the plane of the geosynthetic and the fluid is captured over a large surface, which can lead to high flow rates. To avoid the drainage system being clogged and to ensure a constant flow rate, the drainage system is always used in conjunction with a filter on the side of the soil to be drained, and this retains soil particles. The drain’s capacity to evacuate water in its plane is characterized by transmissivity. Drains are used in many civil engineering projects for accelerating the consolidation of soils, reducing interstitial excess pressures within structures, evacuating runoff water and leachates, and contributing to the lowering of the water table.
Figure 1.3.Drainage function – collecting fluids.
1.2.4. Reinforcement
Reinforcing soil is an ancient technique that consists of combining soils of mediocre quality with reinforcements whose higher tensile strength will compensate for the shortcomings of the local soil. The technique of using geosynthetics to reinforce soil has been used for many decades now in geotechnical projects. It makes it possible to both improve the stability of the structures and to permit greater deformations before failure occurs.
Because of their mechanical properties, reinforcement geosynthetics contribute to the reinforcement of soils of low bearing capacity. They act as a framework in retaining structures, add stability to sealing layers on slopes, limit the magnitude of collapses and counteract landslides. The materials chiefly used as reinforcement are woven GTX or knitted GTX that include reinforcing elements in one or more directions or open-mesh geogrids that allow greater interlocking with granular soils. Reinforcement geosynthetics are designed to resist tensile forces.
There are several ways of creating tension in the geosynthetic. In some cases, the displacement of the soil leads to tensile forces in the reinforcing material (Figure 1.4). In this case, the geosynthetic confines the soil, and this increases its strength.
In some applications, such as reinforcement over a cavity, the soil movement on the reinforcing layer during the opening of the cavity creates forces that act mainly perpendicular to the plane of the geosynthetics that curves (membrane effect), thus allowing the development of tensile forces that are opposed to the action of the collapsed soil (Figure 1.5).
Figure 1.4.Reinforcement through soil displacement.
Figure 1.5.Reinforcement geosynthetic: creating tension through a membrane effect and through friction.
In other cases, it is the geosynthetic that is displaced with respect to the soil (e.g. anchor zone) (Figure 1.5). The relative displacement between the soil and the geosynthetic induces shear forces at the interface that create tension in the reinforcement. The optimization of the interface characteristics, which depend on the texture and roughness of the reinforcement, is essential for optimal reinforcement (a smooth interface characterized by low interface friction does not result in a significant transfer of tangential forces from the soil to the geosynthetic).
Therefore, the basic characteristics required for designing reinforcement geosynthetics are their tensile stiffness, the resistance to tension, deformation under maximum load and their interface properties (which must be determined based on the soil type or the reinforcement geosynthetic being used).
1.2.5. Sealing
The sealing function is essential to limit the transfer of fluids from one medium to another, especially to protect the environment from pollutants (waste storage centers) or to conserve water resources (retention basins, reservoirs and canals) (Figure 1.6). The sealing function is performed by GBR and bentonite geosynthetics. Their ability to allow a fluid to pass through in a direction perpendicular to their plane is described as “permittivity”. When used in a sealing product, sealing geosynthetics are not intended to play a mechanical role and for this reason they are often used in conjunction with other geosynthetics such as protection or reinforcement geosynthetics.
Figure 1.6.Sealing geomembrane.
1.2.6. Protection
Some geosynthetics can be easily damaged when directly exposed to static or dynamic forces from puncturing elements (granular material, scrap material, debris, etc.). To prevent perforation (Figure 1.7), it is essential to use a protection geosynthetic.
Figure 1.7.Protection of a geomembrane against puncture by angular granulates.
This material must have the adequate anti-puncturing mechanical characteristics to limit the damage to the underlying product.
1.2.7. Erosion protection
The erosion of slopes by rainwater or wind has a negative result: over time, could compromise the stability of the structures. In the case of the banks of canals and navigable waterways, repeated wave action is the cause of the scouring that can be observed at the level of the impact zone. To limit the movement and dislodging of granular particles on the surface, it is necessary to take erosion–protection measures (Figure 1.8).
For slopes and embankments subject to gully erosion or wind action, erosion–protection measures must protect surface soils long enough for hardy vegetation to be able to establish itself. Geosynthetics able to do this are of varying designs. They generally have an open mesh and are three-dimensional in nature in order to hold the soil in place and allow plant cover to develop. For banks subject to wave action, compact products, sometimes weighted down, can be used.
Figure 1.8.Erosion protection geosynthetic: protection against rain, wind, and wave action.
1.2.8. Crack inhibition
The use of a geotextile or geotextile-related product, sometimes impregnated with bitumen and integrated in a wearing course, makes it possible to slow down the development of reflective cracking (Figure 1.9). The goal of this technique is to extend the lifespan of roadways in order to minimize the number of maintenance and rehabilitation operations required. The CFG has drawn up “general recommendations for the use of geosynthetics as a means of slowing down the development of reflective cracking in roadways”. It must be noted that in addition to the “stress relaxation” function and the creation of a barrier (sealing layer) that geosynthetics offer, it may be helpful to add a reinforcing component in the fight against reflection cracking in roadways. This is often achieved by incorporating glass fibers in the GTX being used. The crack-inhibition function is chiefly used in treating roadways and airport runways.
Figure 1.9.Crack-inhibition geosynthetics for wearing courses.
1.3. Properties of geosynthetics and principal characterization tests
1.3.1. Mechanical properties
The mechanical behavior of GTX depends on the nature of the base polymer, the manufacturing process of the reinforcing elements and the finishing process used. Mechanical properties can differ depending on the direction of production: machine direction (MD) or cross machine direction (CMD), especially for reinforcement geosynthetics.
1.3.1.1. Tensile behavior of geosynthetics
A knowledge of how geosynthetics behave under tension is essential when characterizing products. The mechanical characteristics of GTX and GTP are generally determined in tensile tests carried out on wide-width strips (the standard EN ISO 10319; BSI 2015b). For sealing geosynthetics, the tensile test differs depending on the nature of the product: GBR-P, GBR-B or GBR-C.
The test involves subjecting samples that are 20 cm wide and 10 cm long to tensile stress at a constant strain rate of 20% per minute. The load-strain curve (Figure 1.10) allows us to determine the tensile strength T, defined per meter of width (kN/m), the strain under maximum force εTmax (%), the secant stiffness J (kN/m) calculated for a reference deformation εc and the quantity of energy absorbed (the area under the load-strain curve). The stiffness J of the geosynthetic affects both the deformability of the structure in which it is used and its behavior in use. The maximum tensile strength, Tmax, and maximum strain, εTmax, have a bearing on possible failure of the structure.
These characteristics may evolve over time, and this applies especially to creep deformation in the base materials, or to the results of chemical or mechanical alteration processes. This is especially important for structures reinforced using geosynthetics. To evaluate the creep deformation under tensile load, geosynthetic samples are subjected to a constant rate of loading (EN ISO 13431; BSI (2006b)). This allows for determination of the creep-rupture resistance as well as the evolution of strain under a constant force for a predefined service life of the structure (isochrone curves).
Figure 1.10.Typical load-strain curve for a tensile test on a geotextile and geotextile-related product (EN ISO 10319; BSI 2015b)
1.3.1.2. Resistance to puncture and perforation
When in use, geosynthetics may experience a drop in their physical and mechanical properties following local damage (which can extend up to perforation). These damages are the result of contact between the geosynthetic and angular elements (contact with granular soil, falling blocks, etc.).
Tests of puncture or perforation resistance aim to test the geosynthetic’s ability to resist static or dynamic local forces. Depending on the type of test, the mechanical characteristics are as follows: puncture resistance (expressed in kN) or the dynamic perforation value (expressed in millimeters). These characteristics depend on the thickness, the mechanical properties of the base elements, the manufacturing method and the internal structure of the geosynthetic. The main standardized tests are as follows (Figure 1.11):
The static puncture test (CBR): EN ISO 12236 (BSI
2006a
). This test consists of determining the rupture force, in kN, required to push a flat-headed cylinder through the geosynthetic. The load is applied perpendicular to the sample at a constant velocity of 50 mm/min. This enables definition of the static puncture resistance of the product.
Dynamic perforation test (cone-drop test): EN ISO 13433 (BSI
2006c
). This test consists of dropping a conical steel object from a predefined height (0.5m) onto a geotextile held horizontally between two clamps. After the impact, the diameter (in millimeters) of the hole created is measured. The smaller the value obtained, the greater the geosynthetic’s resistance to perforation. This test makes it possible to determine the product’s resistance to dynamic perforation.
Figure 1.11.(a) Static puncture tests and (b) dynamic perforation test.
1.3.2. Hydraulic properties
1.3.2.1. Permeability perpendicular to the plane and permittivity
A geotextile’s ability to allow water to pass through in a direction perpendicular to its plane is necessary to limit excess pressures in geotechnical structures. The behavior of the geotextile with respect to water flows is usually characterized by the coefficient of permeability normal to the plane, expressed in m/s (the ability to allow the passage of a fluid under the influence of a hydraulic gradient). The tests may be carried out without mechanical loading under a constant hydraulic load (standard EN ISO 11058; BSI 2019) or under a specific compression load (standard EN ISO 10776; BSI 2012). During the tests, the geosynthetic is subjected to a constant, unidirectional flow perpendicular to its plane (Figure 1.12). The permeability
